Language: The Toba Batak language is related to, but separate from that of other Batak people. The various “tribes” have been described as five, six, or seven Indonesian ethnic groups. These include the Toba, Karo, Pak-pak, Dairi, Angkola, Simalungun, and Mandailing. The Dairi and Pak-pak are also sometimes listed as the same group. Among these, the Toba Batak are the largest group with about two million (2,000,000) speakers of the language.

Note that although there are just 225 or so languages in the World Almanac list it is by no means a complete list of the world's languages. It only lists those with at least two million speakers. In Indonesia alone there are between 350 and 700 different languages, depending on which reference you use and how you define what is a distinct "language". World wide there are an estimated 6,000 different languages. This means, of course, that most have only a few speakers and quite of few are in danger of becoming extinct.
The word for "ceremony" is "gondang" in Toba Batak. The ceremony in Bahasa Indonesia is "upacara". Here are some examples of English, Indonesian and Toba Batak word and phrase comparisons:

This page will continue to accumulate information as I discover it, about the Toba Batak people of Sumatra. Searching the internet does not yield much information, so hopefully this will eventually provide a bit more in organized fashion for those interested.